Regular exercise changes the structure of our bodies’ tissues in obvious ways, such as reducing the size of fat stores and increasing muscle mass. Less visible, but perhaps even more important, is the profound influence exercise has on the structure of our brains – an influence that can protect and preserve brain health and function throughout life. In fact, some experts believe that the human brain may depend on regular physical activity to function optimally throughout our lifetime.
Here are just a few ways exercise changes the structure of our brain.
Many studies suggest that exercise can help protect our memory as we age. This is because exercise has been shown to prevent the loss of total brain volume (which can lead to lower cognitive function), as well as preventing shrinkage in specific brain regions associated with memory. For example, one magnetic resonance imaging (MRI) scan study revealed that in older adults, six months of exercise training increases brain volume.
Another study showed that shrinkage of the hippocampus (a brain region essential for learning and memory) in older people can be reversed by regular walking. This change was accompanied by improved memory function and an increase of the protein brain-derived neutropic factor (BDNF) in the bloodstream.
BDNF is essential for healthy cognitive function due to its roles in cell survival, plasticity (the brain’s ability to change and adapt from experience) and function. Positive links between exercise, BDNF and memory have been widely investigated and have been demonstrated in young adults and older people.
BDNF is also one of several proteins linked with adult neurogenesis, the brain’s ability to modify its structure by developing new neurons throughout adulthood. Neurogenesis occurs only in very few brain regions – one of which is the hippocampus – and thus may be a central mechanism involved in learning and memory. Regular physical activity may protect memory in the long term by inducing neurogenesis via BDNF.
While this link between exercise, BDNF, neurogenesis, and memory is very well described in animal models, experimental and ethical constraints mean that its importance to human brain function is not quite so clear. Nevertheless exercise-induced neurogenesis is being actively researched as a potential therapy for neurological and psychiatric disorders, such as Alzheimer’s disease, Parkinson’s disease and depression.